Electrolytic cell for decomposing water



Jan. 13, 1931.

ELECTROLYTIC CELL FOR DECOMPOSING WATER Filed May 24, 1929 Patented Jan.13, 1931 UNITED STATES PATENT OFFICE ARNO EWALD ZDANSKI, 0F BERLIN,GERMANY, ASSIGNOR T0 BAMAG-MEGUIN AKTIEN- GESELLSCHAFT, OF BERLIN,GERMANY ELECTROLYTIC CELL FOR DECMPOSING WATER Application led May 24,1929, Serial No. 365,711, and in Germany November 14, 1928.

In electrolytic cells for the decomposition of water, it is endeavouredto employ a low cell voltage in order that the consumption of currentmay be as small as possible in relation to the gas produced. This effectcan be obtained by taklng care that the resulting gas bubbles areremoved `is quickly as possible from the zone situated between thevcathode and the anode, since otherwise they form a resistance andthereby increase the voltage for a given load. The cell voltage may alsobe reduced by making the surface of the electrode larger than itsappurtenant projection surface, which can be done, inter alia bydisposing in front of the basal electrode, electrodes consisting, forexample, of perforated sheet iron. By this means the gas bubbles passout of the zone between the cathode and the anode sooner than in thecase of solid electrodes, in which the gas bubbles travel to theoutermost edges of the electrode and set up considerable resistance.`I-Iowever, the surface is not substantially increased in comparisonwith the appurtenant projection surface.

It is also known to employ fore-electrodes` consisting of packets offine wire gauze. In

'this case the effective surface is greater, but

the passage of the gas towards the side facing the' basal electrode isimpeded, since the superimposition of the several layers of gauzeobstructs the fine meshes ofsame `The present invention combines theadvantages of said arrangements Whilst obviating their defects, andconsists in that the foreelectrode employed is composed of only a singlewire gauze, of wide mesh and strong wire, for example, wire with adiameter of 0.6-1.4 mm. with 3-6 meshes per centimetre. The use of sucha woven electrode enables the liberated gas bubbles to pass directly andimmediately towards the side facing the basal electrode, so that theycannot offer any resistance to the passage of the current. In thefore-electrode, the entire superficial area of the wires composing thefabric acts as electrode surface.

For example, the ratio between the total superficial area of a fabricaccording to the lower ends and results from the resistance of thewires, a further development of the invention consists in securing thegauze vby means of a number of studs distributed over its entiresurface. Since each stud has only to supply a small zone of the gauzewith current, the voltage drop is naturally quite small, and it can bereduced practically to zero by employing a suitably large numberofbolts. The method of attaching the studs to the gauze is, of course, animportant matter and it has been found particularly advantageous tosecure the gauze by means of pins driven into bores in the studs. y

The employment of the fore-electrode according to the invention affordsthe great advantagethat, owing to the absence of resistance, and to theincreased surface obtained, a higher electrical loading can be appliedto the surface than in the case of4 other foreelectrodes, withoutthereby increasing the consumption of current.

With the novel woven electrode, the dimensions of the apparatus for agiven outputare V'considerably smaller than heretofore, and themanufacture is simpler and cheaper inasmuch as only a single gauze isprovided instead of the packets previously employed. Of course, severallayers of gauze may also be employed, in which case a wider mesh isused.

The drawing illustrates a typical embodiment of the invention, Fig. 1being a plan and Fig. 2 a side elevation of the electrode, whilst Fig. 3shows one of the yfixing studs on a larger scale.

The fore-electrode gauze 2 is secured to the basal electrode 1 by meansof studs 3 and headed pins 4 driven into the latter.

In order to attach the gauze rmly to the studs 3, the pins 4 are taperedand are simply driven into bores in said studs. Since the studs, whichare passed through and fixed in the basal electrode, are intended -tocarry gauze on both sides, they must form a liquidtight joint. Aparticularly advantageous method of fixing the studs in the basalelectrode consists in providing each stud with a shoulder 5, which isused for tamping or caulking the stud on to the electrode (see the arrowin Fig. 3).

I claim 1. In or for an electrolytic cell for the decomposition ofWater, the combination of a basal electrode, a fore-electrode consistingof a stout Wire gauze of Wide mesh, a plurality of bored studsdistributed over the surface of the basal electrode, and pins driventhrough the gauze into the bores of the studs to secure thefore-electrode.

2. In or for an electrolytic cell for the decomposition of Water, thecombination of a basal electrode, a fore-electrode consisting of a stoutWire gauze of Wide mesh, a plurality of shouldered and bored studsdistributed over the surface of the basal electrode and secured in holestherein by tamping, and pins driven through the gauze with the bores ofthe studsto secure the fore-electrode.

In testimony whereof I affix my signature.

ARNO EWALD ZDANSKI.

